Automatic switch



Oct. 30, 1923.

0. F. FORSBERG ET AL AUTOMATIC SWITCH //7 vem0r5: 0560/ F ForsbergPatented Oct. 3 0, 1923.

YORK, ASSIGNORS TO WESTERN ELECTRIC ROBERT 1!. DE VIGNIER, E HOLLIS, NEWCOMPANY INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

AUTOMATIC SWITCH.

hpplication lled August 13, 1919. Serial 1T0. 317,126.

To all whom it may concern:

Be it known that we, OsoAn' F. FORSBERG and ROBERT M. DE VIGNIER,citizens of the United States, residing at Yonkers, in the county ofWestchester and State of New York, and at Hollis, in the county ofQueens and State of New York, respectively, have invented certain newand useful Improvements in Automatic Switches, of which 1 the followingis a full, clear, concise, and

exact description.

This invention relates to improvements in automatic switching devicesand more particularly to improvements in the mechanical structure of anautomatic switch suitable for in telephone exchange systems.

It has been found that step-by-step switches of small capacity are adated to a variety of uses in automatic tele one exchange systems, whereinthey may be used as line switches, as controlling, auxiliary, or sideswitches, as registers, or as cord or trunk finders. These and otheruses are well understood by those skilled in the art.

It is the object of this invention to provide a switch which shall below of cost and simple in construction and at the same time rapid andefiicient in operation.

A feature of theinvention is the utiliza- I tion of a contact bank whichis in the form of a half cylinder and which is served by two brush sets180 apart. This allows ample space between contacts and also providesthe advantages of a cylindrical bank with none of thedifiiculties ofmounting which are present in a contact bank which form a complete.cylinder. I

An additional feature of the invention is the mounting of the steppingpawl, which has a simple, compact structure capable of r a high speed ofoperation and Without small pivots which would normally tend to loosenand rattle in a high speed switch.

Further features of the invention will be found in structural detailswhich allow of ease of assembly, and ad'usting devicesby means-ofwhichthe switc can be kept in a high state of efiiciency.

It is thought that the invent-ion will best be understood from thefollowing detailed description, reference being bad to the accompanyingdrawings. I t

In the drawings, ig. 1 shows a perspective view of the switch; Fig. 2 isa perspective view showing an adjustable stop which limits the movementof the armature proper of the stepping magnet. m

Two brush sets are provided and are arranged 180 apart. The contact bankextends through an arc of 180, with the result that when one brush setsteps oil the last contact set in the bank, the other set of brusheswill engage the first contact set in the bank. Each brush is composed-oftwo wiping members, as 3 and 3', and a multiple brush, which is 180beyond it in revolution, is integrally made up from the members of 3 and3' so that two multiple brushes are made up from one pair of punchings.The edges 4 and 4' are suitably ofiset so as to wipe over the contactsin the bank and to be forced apart when in engagement with a contact, sothat the portion 4 will be above the contact and in engagement therewithand the contact 4 contact and in en agement therewith. An desired numberof brushes may be provide In the embodiment shown in Fig. 1, six brushsets are shown with a correspondin set of six brush sets in multiplewith them. The various sets of brushes are mounted on a rotatable shaftand suitably insulated from one another. Current is led into the brushesby means of conducting strips, such as 10, which are mounted in the bankin the same manner as the contact sets. The inner portions of theconducting strips 10 are arranged to bear constantly on circularportions of the punchings 3, so that as the brushes rotate the members10 will be constantly in engagement. with them. On the same shaft withthe brushes 3, and in fixed relation thereto is a circular indicatingplate 11 which cooperates with an adjustable pointer 12 secured to theframe 9 and adjust-' able by means of screw 13 to indicate with whichparticular contact set the brushes are in en agement. This indicator maybe used to in. orm an attendant in what osition the switch is resting incase of troub e. Secured to the lower ortion of the shaft is a ratchetwheel 14. Tlie shaft, with the indicator 11 the various brush sets, andthe ratchet whee 14 is suitably mounted for rotation.

A ma et 15 is provided to impart motion' to t e switch. Connectionterminals 16 and 17 are provided for introducing the conwill beunderneath the longer arm 25 of the and 21 of the main frame punching 9.The

punching from which the armature is made is bent into a U shape with oneof the branches of the U longer than the other. The shorter branch 22 ofthe U, is connected by means of a spring is part of the main framepunching. The U, is brought forward a sufiicient distance to carry thestepping pawl. An insulated lug 26 is arranged to co-operate with aspring member 27, to operate the contact set included by the members 28and 29. This contact may be utilized to make the stepping magnetself-interrupting. Also secured to arm 25 is a resilient connectingportion, or reed 30 which is fixedly secured to the arm 25 by means ofscrews 31 and 32. To the free end of thereed 30 is securely fastened astepping pawl 33 which may be riveted to the reed or rigidly securedthereto in any desired manner. Th pawl 33 is .made to co-operate withthe ratchet wheel 14 by means of an adjustable block 34 which throws theend of the pawl into engagement with the teeth of the ratchet wheel 14.The block 34 is made adjustable in slot 35 of the frame to insure roperregistration between th pawl and t e teeth of the ratchet. i

A resilient holding pawl 36 is proyided to hold the brushes in theirproper position and to prevent backward movement of the ratchet wheel.The holding pawl 36 may be adjusted longitudinally by means of a screw37 which secures it to frame 9 through a slot in the pawl 36. A pin 38,secured to the frame and movable in the slot 39 of the pawl, allowslongitudinal adjustment. ofthe pawl and at the same time preventslateral movement thereof.

The contact bank indicated at 40 is made up from a number of rows ofterminals 41 arranged man are and clamped together by means of thearc-shaped binding members 42 and screws 43. The lower binding arecorresponding to 42 is not shown, but since this type of construction iswell-known, it is thought that it will be readily understood withoutfurther description.

The contacts 41 are suitably insulated from on another in any desiredmanner. Similarly, the various rows ofcontacts are suitably insulatedfrom one another in the make-up of the contact bank.

At 44, 45 and 46, are shown solid strips 23 to an arm 24 which it is ascheap to supply any necessary oil'- normal contacts in this manner sincethe small mechanisms incident to the provision of the usual type ofoff-normal contact are thus eliminated.

Referring now to Fig. 2, an adjusting member 47 is shown, to limitthemovement of armature 18. In accordance with the setting of this stop,the movement of the armature may be made to correspond to a stop advanceof the ratchet wheel. After it has been properly set, it may be lockedin adjusted position by tightening screw 48.

Briefly, the operation of the switch is as follows. When the armature 18is attracted,

the arm 25 is moved back to register with another tooth of the ratchetwhee-l 14. The resiliency of reed 30 allows sufficient lateral movementof pawl 33 to enable it to ride over the tooth; at the same time spring23 is tensioned. When magnet 15 is deenergized the tension in spring 23restores the armature 18 to its normal position and throws pawl 33forward and advances the ratchet Wheel one step. During this forwardstroke the reed 30 and the pawl 33 are moving in parallel relation.There is no tendency for the reed 30 to bend and ample power may betransmitted through it.

The advantage of this type of mounting for a pawl is obvious. If apivoted pawl is provided the wear on the pivot is sure to causelooseness and rattling which cannot be eliminated by adjusting. If areed pawl is provided, that is a pawl in which the reed itself operatesas a stepping pawl, it is difiicult to provide the proper weight andmaterial and still hav the pawl sufiiciently resilient. If sufiicientresiliency is obtained, it is very likely that the pawl will not bestrong enough to function properly. In the present invention there canbe no wear which would cause looseness or rattling except perhaps in thepoint of the pawl itself and if this occurred it could readily beeliminated by adjusting the stop 34.

What isclaimed is:

1. In an automatic switch for use in telephone exchange systems, powermeans' comprising a ratchet wheel, a pawl in operative relation thereto,a stepping magnet, an armature for said stepping magnet, and a resilientdriving member, having one end rigidly secured to said armature, and theother end rigidly secured to said. pawl.

2. In an automatic switch for use in telephone exchange systems, a framefor said switch, ratchet and pawl mechanism for controlling the movementof said switch, a stepping magnet, an armature for said magnet,controlling arms integral with said arma ture, a resilient drivingmember between one of said arms and said stepping pawl, said connectingmember being rigidly connected at one end to the last named arm and atthe other end to said stepping pawl, a spring connection between theother controlling arm and said frame, means to actuate said steppingpawl in response to operation of said magnet, and means to advance saidratchet wheel upon deenergization of said magnet due to the retractilepower of said spring connection.

3. In an automatic switch for use in telephone exchange systems, aratchet and pawl mechanism for causing movement of said switch, astepping magnet, an armature therefor, a resilient driving member havingone end rigidly secured to said armature and 5 the other end rigidlysecured to said stepping pawl, and means to adjust the extent ofmovement of said pawl. I

4. In a progressively operable mechanism, power means comprising aratchet wheel, a pawl in operative relatlon thereto, a step ping magnet,an armature for said stepping magnet, a resilient connecting member having one end secured to said armature and the other endsecured to saidpawl, and means for applying power to said pawl by applying tension tosaid connecting member. In witness whereof, we hereunto subscribe ournames this31st day of July A. D., 1919.

OSCAR F. FORSBERG. ROBERT M. on VIGNIER.

